The oxygen reduction/evolution reactions (ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices, such as metal-air batteries and reversible fuel cells. The search for low-cost high-performance nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER alternatives to the widely-used noble metal-based catalysts is a research focus. This review aims to outline the opportunities and available options for these nanocarbon-based bifunctional electrocatalysts. Through discussion of some current scientific issues, we summarize the development and breakthroughs of these electrocatalysts. Then we provide our perspectives on these issues and suggestions for some areas in the further work. We hope that this review can improve the interest in nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER.

氧还原/放出反应（ORR / OER）是电化学能量转换和存储设备（如金属-空气电池和可逆燃料电池）开发中的关键电极工艺。寻找低成本，高性能的纳米碳基无金属和非贵金属双功能电催化剂，以替代广泛使用的贵金属基催化剂的ORR / OER替代品。这篇综述旨在概述这些基于纳米碳的双功能电催化剂的机会和可用的选择。通过讨论一些当前的科学问题，我们总结了这些电催化剂的发展和突破。然后，我们对这些问题提出了自己的看法，并为进一步的工作提供了一些建议。